Anthracene-based hetero bisamide chemosensor in fluorescence sensing of monocarboxylates over monocarboxylic acids

A fluorescent chemosensor 1 with different amide moieties as recognition elements has been designed and synthesised. The recognition behaviour of the chemosensor towards various monocarboxylates and their conjugate acids has been evaluated. Although the sensor 1 shows significant quenching of emission of anthracene in CH₃CN, it shows an increase in emission in CHCl₃ containing 2% CH₃CN upon complexation of aliphatic monocarboxylates. Receptor 1 shows selectivity for acetate, propanoate and dihydrogen phosphate over the other anions studied under different conditions. The binding features have been established by ¹H NMR, UV–vis and fluorescence spectroscopic methods.